Filtering Assembly Comprising a Filter Cartridge

ABSTRACT

The present invention relates to a filtering assembly ( 1 ) for filtering at least one fluid circulating in particular in an engine or a hydraulic device, comprising: a filter body ( 2 ), which comprises a vessel ( 3 ) and a head ( 4 ), the vessel ( 3 ) and the head ( 4 ) being provided to engage with one another in order to close the filter body ( 2 ), in particular by screwing; a tube ( 15 ), in particular a central tube, which is inside the filter body ( 2 ) and extends along a longitudinal axis (X); a removable filtration cartridge ( 16, ) which is accommodated in the filter body ( 2 ) and includes an upper end plate ( 20 ), a lower end plate ( 21 ) and a filtration medium ( 22 ) which extends between the upper ( 20 ) and lower ( 21 ) end plates, the filtering medium ( 22 ) having a tubular opening ( 17 ) for surrounding the tube ( 15 ), characterized in that the upper end plate ( 20 ) comprises first reversible rigid-connection means ( 25 ) and in that the vessel ( 3 ) comprises second reversible rigid-connection means ( 26 ) which are complementary to the first reversible rigid-connection means ( 25 ), such as to enable the filtration cartridge ( 16 ) to stay in position in the vessel on the one hand, and in the filtering assembly ( 1 ) on the other hand, only by rigidly connecting the first and second reversible rigid-connection means ( 25, 26 ).

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a National Stage of PCT Application No.PCT/EP2015/054113 filed Feb. 27, 2015, which claims priority to FrenchPatent Application No. 1451929, filed Mar. 10, 2014. The contents ofboth applications are incorporated herein by reference in theirentirety.

FIELD OF THE INVENTION

The field of the invention is the design and production of filterassemblies used to filter fluids circulating particularly in motors orhydraulic equipment, the fluids essentially being oil or fuel.

Such filter assemblies are generally composed of a filter body,comprising a receptacle or shell and a head inside which a removablefiltration cartridge is disposed, having a filtration medium generallycylindrical in shape surrounding a tubular hole and which can be made ofpaper, for example, cardboard or felt or another porous material, suchas a synthetic or non-synthetic unwoven material. The filtrationcartridge also comprises two end caps demarcating the filtration mediumand allowing the installation of the filtration cartridge inside thefilter body.

Such a filtration cartridge generally cooperates with a tube,particularly central, which may or may not be integral with the endcaps, and may or may not be integral with the filtration cartridge, theoutside diameter of which is close to the inside diameter of the tubularhole surrounded by the filtration medium, particularly so as to limitthe deformations of the medium under the effect of the pressure beingexerted inside the filter assembly.

The end caps are formed by an upper end cap and a lower end cap. Thepurpose of the end caps is particularly to participate in sealing thefiltration cartridge and to allow the attachment of the filtrationcartridge to the permanent part of the filter assembly.

The filtration cartridge is removable in order to allow its replacementwhen it has reached the end of its working life, by a new filtrationcartridge.

PRIOR ART

Known filtration cartridges comprise, in addition to the filtrationcartridge, at least one gasket to form the seal between the head and thereceptacle. An additional gasket can be added between the upper end capand a threaded holder.

Moreover, known filter assemblies comprise means for holding thefiltration cartridge in position inside the receptacle, generallycomprising a threaded holder, a collar, a gasket between threaded holderand collar, and a spring.

Such filter assemblies therefore comprise a significant number ofdifferent parts, generally more than 11 different parts for a so-calledspin-on filter. There is thus a need to reduce the number of differentcomponents to produce a filter assembly of this type.

Moreover, as regards ecological concerns, there is a need to limit thequantity of discarded material when the filtration cartridge isreplaced.

OBJECTIVES OF THE INVENTION

An objective of the invention is especially to respond to all or part ofthese needs.

In particular, according to at least one embodiment, an objective of theinvention is to provide a filter assembly with a limited number ofparts, especially fewer than or equal to five different parts.

Another objective of the invention is to minimize the number ofmaterials discarded with the filtration cartridge when it is replaced.

Another objective of the invention is to provide an efficient filterassembly, particularly in terms of sealing, without adding additionalgaskets.

DESCRIPTION OF THE INVENTION

To achieve all or part of these objectives, the invention proposes afilter assembly to filter at least a circulating fluid, especially in amotor or hydraulic equipment, comprising:

-   -   a filter body having a receptacle and a head, the receptacle and        the head being provided so as to cooperate together to close the        filter body, especially by screwing,    -   a tube, especially central, inside the filter body extending        along a longitudinal axis (X), the tube being integral with the        head or the filtration cartridge,    -   a removable filtration cartridge housed in the filter body and        comprising an upper end cap, a lower end cap and a filtration        medium extending between the upper and lower end caps, the        filtration medium having a tubular hole to surround the tube,

characterized in that the upper end cap has first reversible securingmeans and in that the receptacle includes second reversible securingmeans complementary to the first reversible securing means, so as toenable the filtration cartridge to be maintained in position in thereceptacle on the one hand, and in the filter assembly on the otherhand, solely by the securing of the first and second reversible securingmeans.

Thanks to the invention, the filtration cartridge is held in position asa result of the securing of the upper end cap to the receptacle, whichin particular avoids having to provide additional means to allow thefiltration cartridge to be held in the filter body. In this way, thenumber of parts comprising the filter assembly can be reduced.

The upper end cap can be composed of a single part and comprises a firstelement made of a first material and a second element made of a secondmaterial, the upper end cap being formed by overmolding of the secondelement onto the first element.

For example, the first element can be made of a rigid material while thesecond element can be produced from a flexible material providing thenecessary seal, without adding separate gasket(s).

The first material, for example, comprises a polyamide resinparticularly allowing the overlay of the filtration medium, theproperties of which advantageously allow the filtration cartridge to beheld rigidly in the receptacle.

The second material for example is chosen from the group composed of athermoplastic elastomer, a synthetic or natural rubber, or vulcanized,having properties that allow a compression set compatible with a sealingfunction. The second material can then be of any other material havingthe property of being able to be overmolded onto the first material, andadvantageously having hardness characteristics that are compatible withthe sealing function.

The second element of the upper end cap can be configured to ensure atleast one seal with respect to the exterior of the filter body, whileensuring the seal between the inside and outside of the filter bodywhere the head and receptacle cooperate.

As a result of this aspect of the invention, the seal of the closure ofthe filter body is ensured by the upper end cap of the filtrationcartridge, which has the particular advantage of not needing theaddition of another gasket, for example a ring seal or O-ring or collar.

The tube can form part of the filtration cartridge or of the head, inwhich case it is reusable. For example, the tube extends in proximityto, especially in contact with, the filtration medium, demarcating aninner space of the tube. The tube can be free and not have a sealingfunction.

The first and second reversible securing means cooperate for example bysnapping on, screwing or force fit. As a result of this mode ofcooperation, it is easy for an operator to position the filtrationcartridge in the filter assembly or to remove it therefrom. In the eventof force fit, the receptacle and the filtration cartridge remainpermanently integral with one another, and the replacement of thefiltration cartridge during a maintenance operation involves thesimultaneous replacement of the receptacle.

In this case, the first reversible securing means include for example atleast one snap-on tab, particularly produced in the first element of theupper end cap. The second reversible securing means comprise for examplea rib protruding towards the interior of the filter body, particularlyproduced in an upper portion of the receptacle and extending over theentire perimeter of the receptacle.

Such an embodiment requires the formation of the rib when the receptacleis manufactured, said rib being for example produced in or nearthreading enabling the head to be secured to the receptacle to the headby screwing. The rib can for example have a V shape in longitudinalcross-section. The seal between [the] second element of the upper endcap is, at the receptacle, advantageously formed by the rib which worksin axial compression on the one hand and the vertical wall of thereceptacle working in radial compression during swelling of the secondmaterial on the other hand. The seal at the head is for example providedby a shape of the head complementary or not to the shape of the secondmaterial. The invention makes it possible to reduce the number of parts,thus enabling a direct seal between receptacle and head, contrary to ascrewed filter of the prior art, in which a collar inserted between headand receptacle requires having two seals in the receptacle/collar/headseries.

The first and second reversible securing means are advantageouslyconfigured to ensure that the filtration cartridge is held in positionlaterally and vertically. Thanks to this aspect of the invention, thefiltration cartridge does not need additional means to maintain itinside the filter body, which again decreases the number of partsnecessary to produce the filter assembly.

The receptacle can have a substantially cylindrical wall and a bottom.In this case, the upper end cap has for example a generally ring shapewith an outside diameter substantially equal to the inside diameter ofthe substantially cylindrical wall of the receptacle. The filtrationmedium has an outside diameter that can be smaller than the outsidediameter of the upper end cap, in such a way that a space, particularlysubstantially cylindrical, is formed between the substantiallycylindrical wall of the receptacle and the filtration medium.

In this latter case, the upper end cap, particularly the first elementof the upper end cap, can include a plurality of openings disposed in aperipheral region of the upper end cap to allow the passage of fluid,particularly the fluid to be filtered, from the head towards said space.

Thanks to the invention, according to this embodiment, the upper end capallows the circulation of the fluid, particularly the fluid to befiltered, while ensuring that the filtration cartridge is held inposition by its cooperation with the receptacle.

Advantageously, the head can include an intake duct for the fluid to befiltered and an outlet duct for the filtered fluid. In this case, thelower end cap can be configured to form a plug preventing any filteredfluid from flowing towards the bottom of the receptacle.

Thus, according to this embodiment of the invention, the filtered fluidwill be able to be evacuated by a filtered fluid outlet duct located inthe head, passing through a central opening of the upper end cap. Inthis embodiment, the filtered fluid outlet duct can be produced in thehead of the filter body.

LIST OF FIGURES

Other characteristics and advantages of the invention will be seen fromthe following description of a particular embodiment thereof, providedby way of simple illustrative and non-limiting example, and from theappended drawings in which:

FIG. 1 is a schematic illustration in perspective of a filter assemblyaccording to one embodiment of the invention;

FIG. 2 represents schematically, partially in cross-section, partiallyin perspective, the filter assembly of FIG. 1;

FIG. 3 represents schematically and in perspective, just the end cap ofthe filter assembly of FIGS. 1 and 2;

FIG. 4 partially, schematically and in perspective represents thecooperation between the upper end cap and the receptacle in theembodiment illustrated in FIGS. 1 to 3;

FIG. 5 represents schematically and partially, in cross-section, thefiltration cartridge cooperating with the receptacle, in the filterassembly of FIGS. 1 to 4, without the head;

FIG. 6 represents schematically and partially, in longitudinalcross-section, the connection of the filtration cartridge with thereceptacle, in the embodiment of FIGS. 1 to 5;

FIG. 7 is a view in longitudinal cross-section, schematically andpartially illustrating the connection between the receptacle and thefiltration cartridge; and

FIG. 8 represents schematically and in perspective the filter assemblyof FIG. 1 without the head.

DESCRIPTION OF ONE PARTICULAR EMBODIMENT

Represented in FIG. 1 is a filter assembly 1 according to one embodimentof the invention having a filter body 2, closed in this example,comprising a shell or receptacle 3 and a head 4. The filter assembly 1also includes a removable filtration cartridge 16, housed in the body ofthe filter 2. The receptacle 3 and the head 4 are intended to cooperatetogether in order to close the filter body, by screwing in this example,as can be seen in particular in FIG. 2. Indeed, the head 4 has threading5 and the receptacle 3 has complementary threading 6 enabling theclosure of the filter body 2 by screwing the head 4 with the receptacle3. It should be noted in this example that the head 4 is attached to theframe of the application (not illustrated). The receptacle 3 isdisconnected from the head 4 when the filtration cartridge is changed.

FIGS. 1 and 2 also illustrate an intake duct 7 for the fluid to befiltered, integrated into the head 4 as well as an outlet duct 8 for thefiltered fluid also integrated into the head 4. The intake duct 7 allowsthe fluid to be filtered to be routed towards a peripheral zone of thereceptacle 3 while the outlet duct 8 for the filtered fluid allows theclean filtered fluid to be extracted from a central portion of thereceptacle 3, as will be explained hereinafter. As can be seen in thefigures, the intake duct 7 and outlet duct 8 comprise respectivethreading 12 and 13 allowing them to be connected by screwing two otherelements, particularly pipes, outside the filter assembly 1, notrepresented in order to maintain clarity of the drawing, for routing thefluid.

In this example the receptacle 3 has a substantially cylindrical wall 35extending along a longitudinal axis X and connected to a bottom 28 ofthe receptacle 3. In the illustrated example, the substantiallycylindrical wall 35 has a widening 36 in such a way that the diameter ofthe receptacle 3 is greater in an upper portion of the receptacle 3 thatincludes the threading 6. Such a widening enables the receptacles to bestacked when they do not contain filtration cartridges, in order tolimit the storage space occupied by empty receptacles. It is obvious ofcourse that if the receptacle 3 does not have this widening, this doesnot go beyond the scope of the invention.

The filter assembly 1 also includes a tube 15, central in this example,inside the filter body 2 and extending along the longitudinal axis X.

The filtration cartridge 16 comprises an upper end cap 20, a lower endcap 21 and a filtration medium 22 extending between the upper end cap 20and lower end cap 21, the filtration medium 22 having a tubular hole 17to surround the tube 15.

According to the invention, the upper end cap 20 has first reversiblesecuring means 25 and the receptacle 3 has second reversible securingmeans 26 that is complementary to the first reversible securing means25, so as to enable the position of the filtration cartridge 16 to bemaintained in the filter assembly 1 simply by the connection of thefirst and second reversible securing means 25 and 26.

In the illustrated example, the first reversible securing means 25includes a plurality of snap-on tabs 27, four in number in theillustrated example. The second reversible securing means 26 comprises arib 29 formed to project into the interior of the filter body 2,produced in this example in an upper portion of the receptacle 3, nearthe threading 6, and extending over the entire periphery of thereceptacle 3. The rib 29 is V-shaped in longitudinal cross section alongthe axis X.

The upper end cap 20 is composed of a single piece, visible in FIG. 3,formed by overmolding onto a first element 30 of a first material, asecond element 31 of a second material. Advantageously the firstmaterial includes a polyamide resin while the second material includes athermoplastic elastomer such as polyurethane. The upper end cap 20 thusincludes the first element 30, more rigid, and the second element 31,more flexible, which confers different functions related to thecooperation, within the same part, of these different materials.

In this example, as can be seen, the first element 30 is substantiallyring shaped and includes the first reversible securing means 25. Thesecond element 31 is intended to form the seal on the inner and outerperiphery of the generally ring shaped upper end cap 20. The secondelement 31 has an outer ring 32 and an inner ring 33, overmolded ontothe first element 30, the first ring 32 and second ring 33 beingconnected in this example by integral bridges 34, four in number in theillustrated example, the bridges 34 also forming part of the secondelement 31. The second element 31 of the upper end cap 20 is configuredto ensure at least the seal with respect to the exterior of the filterbody 2, while playing the part of a sealing gasket between the interiorand exterior of the filter body 2 at the place of cooperation betweenhead 4 and receptacle 3, as can be seen more particularly in FIG. 4.

In the illustrated example, the first and second reversible securingmeans 25 and 26 are configured to ensure that the filtration cartridge16 is maintained in position laterally and vertically.

As can be seen in FIG. 4, the outer ring 32 of the second element 31 ofthe upper end cap 20 comes in contact with the cylindrical inner wall 35of the receptacle 3, at an upper end 40 thereof. The outer ring 32 alsohas, at the lower part, a portion 41 coming in contact with an upperpart 42 of the rib 29 in order to ensure the seal, on the upper arm ofthe horizontal V of the rib 29.

As can be seen in the figure, the tube 15 has a plurality of openings 45allowing the passage of filtered fluid having passed through thefiltration medium 22. In this example, the tube 15 forms a part of thefiltration cartridge 16 and extends in proximity to, and especially incontact with, the filtration medium 22.

The upper end cap 20 has an inner peripheral portion 46 of the firstelement 30 overlying the tube 15, as can be seen in FIG. 4, andsurrounding the filtration medium 22 in its upper end 50. This innerperipheral portion 46 can serve to guide and center the tube 15.

The inner ring 33 of the second element 31 of the upper end cap 20, ascan be seen particularly in FIG. 4, overlays the inner peripheralportion 46 of the first element 31, in the extension thereof, andprovides the inner seal at this position. The shape of the inner ring 33can ensure a radial seal on an ad-hoc shape of the head. This radialseal is reinforced during the increase of differential pressure betweenthe intake and outlet circuits of the filter assembly.

As can be seen in this example, the upper end cap 20 has an outsidediameter that is larger than the outside diameter of the filtrationmedium, so as to provide a substantially cylindrical peripheral space 38between the substantially cylindrical wall 35 of the receptacle 3 andthe filtration medium 22. To enable the flow of fluid to be filteredinto the peripheral space 38, openings 39, visible in particular inFIGS. 3 and 8, are formed in the upper end cap 20, particularly in thefirst element 30 of the upper end cap 20.

In the illustrated example the lower end cap 21 forms a plug that coversfrom the bottom the filtration medium 22 as well as the tube 15, as canbe seen in FIGS. 5 and 6 in particular. The plug formed by the lower endcap 21 makes it possible to prevent any filtered fluid from flowingtowards the bottom 28 of the receptacle 3 in this embodiment.

FIG. 6 illustrates the installation of a filtration cartridge 16, in thedirection of the arrow, inside the receptacle 3 during a replacement. Ascan be seen, the head 4 has first been removed in order to insert thereplacement filtration cartridge 16 and to enable the reversibleconnection between the first and second reversible securing means 25 and26.

Thanks to the invention, it is not necessary to provide additionalsealing means at the periphery of the filter body in order to form theseal with the exterior of the filter body, or to provide means ofinterior seal to ensure the seal between the head 4 and the upper endcap 20. It is no longer necessary to provide means of holding thefiltration cartridge in position other than the upper end cap 20, whichalso serves this function.

Indeed, the upper end cap 20 provides multiple functions of interior andexterior sealing as well as holding the filtration cartridge inposition, in addition to the conventional function of closure of thefiltration medium, as in a screw-on filter of the prior art. This makesit possible to reduce the number of components and to simplify themanufacture of the filter assembly 1.

Also, as a result of the invention it is not necessary to provide aheight tolerance of the filtration cartridge 16. Indeed, because thefiltration cartridge 16 is, in a manner of speaking, suspended insidethe filter body 2 and held by only one side, the height of thefiltration cartridge does not interfere with the other components of thefilter assembly 1.

The invention is not limited to the example that has just beendescribed. In particular, the first and second reversible securing meanscan cooperate by screwing or force-fit assembly without going beyond thescope of the invention. In the case of force-fit assembly, thereceptacle and the filtration cartridge remain permanently integral, andthe replacement of the filtration cartridge during a maintenanceoperation involves the simultaneous replacement of the receptacle.

It should be noted that drainage means can be provided, in which casethe filter assembly 1 will be modified to do this, without going beyondthe scope of the invention.

Throughout the description, the expressions “including a” and“comprising a” should be understood as synonymous with the expressions“including at least one” and “comprising at least one,” unless otherwisespecified.

1-10. (canceled)
 11. A filter assembly to filter a circulating fluid,comprising: a filter body having a receptacle, the receptacle configuredto be removably coupled to a filter head, a tube positioned inside thefilter body, a filtration cartridge housed in the filter body andcomprising an upper end cap, a lower end cap and a filtration mediumextending between the upper end cap and the lower end cap, thefiltration medium having a tubular opening surrounding the tube, whereinthe upper end cap comprises first reversible securing means and thereceptacle comprises second reversible securing means complementary tothe first reversible securing means, the first reversible securing meansconfigured to engage the second reversible securing means so as tomaintain the filtration cartridge in position in the receptacle solelyby the securing of the first and second reversible securing means. 12.The filter assembly according to claim 11, wherein the upper end capcomprises a single piece comprising a first element made of a firstmaterial and a second element made of a second material, the upper endcap being formed by overmolding of the second element onto the firstelement.
 13. The filter assembly according to claim 12, wherein thefirst material comprises a polyamide resin.
 14. The filter assemblyaccording to claim 12, wherein the second material is selected from thegroup consisting of a thermoplastic elastomer, a synthetic rubber, and anatural rubber.
 15. The filter assembly according to claims 12, whereinthe second element of the upper end cap forms at least one seal withrespect to an exterior of the filter body, while ensuring the sealbetween the inside and outside of the filter body where the filter headand receptacle cooperate.
 16. The filter assembly according to claim 11,wherein the first reversible securing means and the second reversiblesecuring means cooperate by a snap fit.
 17. The filter assemblyaccording to claim 11, wherein the first reversible securing means andthe second reversible securing means cooperate by a screw fit.
 18. Thefilter assembly according to claim 11, wherein the first reversiblesecuring means and the second reversible securing means cooperate by aforce fit.
 19. The filter assembly according to claim 16, wherein thefirst reversible securing means comprises at least one snap-on tab, andwherein the second reversible securing means comprises a rib protrudingtowards the interior of the filter body.
 20. The filter assemblyaccording to claim 11, wherein the first reversible securing means andthe second reversible securing means are configured to ensure that thefiltration cartridge is held in position laterally and vertically. 21.The filter assembly according to claim 11, wherein the first reversiblesecuring means is non-removably secured to the second reversiblesecuring means, such that the replacement of the filtration cartridgeduring a maintenance operation involves the simultaneous replacement ofthe receptacle.
 22. The filter assembly according to claim 11, whereinthe receptacle has a substantially cylindrical wall and a bottom,wherein the upper end cap has a generally ring shape with an outsidediameter substantially equal to an inside diameter of the substantiallycylindrical wall of the receptacle, and wherein the filtration mediumhas an outside diameter that is smaller than the outside diameter of theupper end cap, such that a peripheral space is formed between thefiltration medium and the substantially cylindrical wall of thereceptacle.
 23. The filter assembly according to claim 22, wherein theupper end cap includes a plurality of openings disposed over aperipheral region of the upper end cap so as to allow the passage offluid to be filtered from the filter head towards said peripheral space.24. The filter assembly according to claim 11, wherein the tube isformed as part of the filter cartridge.
 25. A filter assembly forfiltering a fluid, comprising: a filter housing body comprising areceptacle, the filter housing body configured to be removably coupledto a filter head; a tube positioned inside the filter housing body alonga longitudinal axis of the filter housing body; a filtration cartridgeremovably housed in the filter housing body and comprising an upper endcap and a filtration medium, the filtration medium having a tubularopening surrounding the tube, wherein the upper end cap comprises aplurality of snap-on tabs and the receptacle comprises a rib configuredto project into an interior of the filter housing body, the plurality ofsnap-on tabs engaging the rib so as to secure the filtration cartridgewithin the receptacle.
 26. The filter assembly according to claim 25,wherein the filter housing body and the filter head includecomplementary threading thereon for use in coupling the filter housingbody to the filter head.
 27. The filter assembly according to claim 25,wherein the upper end cap comprises a single piece comprising a firstelement made of a first material and a second element made of a secondmaterial, the upper end cap being formed by overmolding of the secondelement onto the first element.
 28. The filter assembly according toclaim 27, wherein the first material comprises a polyamide resin, andwherein the second material is selected from the group consisting of athermoplastic elastomer, a synthetic rubber, and a natural rubber. 29.The filter assembly according to claim 28, wherein the second element ofthe upper end cap forms at least one seal with respect to an exterior ofthe filter body, while ensuring the seal between the inside and outsideof the filter body where the head and receptacle cooperate.
 30. Thefilter assembly according to claim 25, wherein the plurality of snap-ontabs non-removably engage the rib such that the replacement of thefiltration cartridge during a maintenance operation involves thesimultaneous replacement of the receptacle.